Roman conquest of Britain

The Roman conquest of Britain occurred from 43 to 84 AD when the Roman Empire invaded Britannia and subdued the Celtic Britons after over forty years of brutal warfare and failed native uprisings. The Romans pushed as far as Caledonia in central Scotland, although they ultimately established Hadrian's Wall in northern England as the permanent northern limit of the Empire. The Romans would remain the masters of Britain until 410 AD, when they evacuated the island in the face of Angle, Saxon, and Jute invasions.

Background
Cunobelinus, the ruler of the Catuvellauni, expanded his kingdom, encroaching on the territory of the pro-Roman Atrebates. Cunobelinus maintained a friendly stance towards the Romans. After his death in 40 AD, his sons expanded the kingdom further and were unfriendly to Roman interests. Another son fled to Rome, attempting to provoke a Roman invasion.

History
The immediate pretext for the Roman invasion of Britain was the appeal by Verica, the exiled King of the Atrebates, to the Emperor Claudius to help restore him. As a result, four Roman legions - more than 20,000 men - embarked for England in late April 43 AD.

The Claudian invasion force, under Aulus Plautius, established its main base in the sheltered harbor of Richborough in eastern Kent and moved westwards. The Britons, under Caratacus and Togodumnus, the leaders of the Catuvellauni, opposed the advance but were pushed back to the Thames. The Romans found a way across and in the ensuing fighting Togodumnus was killed. A pause in the campaign allowed for the arrival of Claudius himself. The emperor was thus able to direct in person the capture of the capital of Camulodunum (Colchester), before he returned to Rome, basking in the glory of his new conquest.

Roman expansion
The next four years saw the expansion of the Roman-controlled area, as the remnants of the Catuvellaunian kingdom were absorbed, while the future Roman emperor Vespasian mopped up resistance in the south and south-west. By around 47 AD, the Romans had secured a line that ran roughly along the future Fosse Way (from the Devon coast to Lincolnshire) and established a series of forts to cement their control. They then tried to push west into Wales, vigorously opposed by Caratacus, who had escaped to lead a renewed British resistance. He was finally captured in 51 AD after he had fled to the imagined safety of the court of Cartimandua, Queen of the Brigantes, who handed him over to the Roman authorities.

Boudicca's Revolt
In 60 AD, the Romans faced a serious revolt that almost drove them from Britain. Boudicca, the Queen of the Iceni, fearing her territory being incorporated into the Roman province after the death of her husband, King Prasutagus, revolted and marched on Calumodunum. The Roman governor, Suetonius Paulinus, was away in North Wales. By the time he returned, Camulodunum had been razed to the ground, and a detachment of the Legio IX Hispana cut to pieces. Londinium (London) and Verulamium (St. Albans) were burnt to the ground by Boudicca's marauding army. Finally, Paulinus' legions faced the Iceni somewhere in the Midlands. The Roman victory was total; some 80,000 Britons were said to have died, a figure that matches the tally of 80,000 Romans (mostly civilians) who perished during Boudicca's campaign of destruction. The Icenian queen herself died soon afterwards, allegedly by poisoning.

The northern frontier
By the mid-70s, the Brigantian kingdom and the rest of Wales had been annexed, but it fell to Gnaeus Julius Agricola, who arrived in Britain as governor in 78 AD, to project Roman power far into the north of Scotland. Within four years, Agricola had reached the Forth-Clyde line, where he established a number of forts. He then pushed further northwards, launching a combined land and naval assault against the Caledones. In the summerof 83 AD, he won a crushing victory at Mons Graupius (probably somewhere near Inverness). Resistance to the Romans crumbled and Agricola established a legionary fortress at Inchtuthill on the Tay. However, within a few years almost all of his conquests were abandoned.

Aftermath
Northern Scotland was evacuated by Domitian and the garrisons in southern Scotland were also reduced. Emperor Domitian needed troops to conduct a war in Dacia in the mid-80s. Scotland was not a high priority for him and the legion which should have formed the garrison at Inchtuthill was withdrawn and sent to Moesia on the River Danube by 92 AD.

During the reign of Trajan (97-115 AD), Roman garrisons in southern Scotland were thrown out and most forces became stationed in the forts along the Tyne-Solway isthmus between Carlisle and Newcastle. Hadrian's Wall was built close to this line in the 120s AD, forming a new defensive border for Roman Britain.